Auth bypass in Elastic Kibana

CVE-2026-78603

Missing Authorization (CWE-862) in Kibana can lead to information disclosure via Exploiting Incorrectly Configured Access Control Security Levels (CAPEC-180). An authenticated user holding minimal Elasticsearch privileges could bypass Kibana feature authorization and space access controls, resulting in the unauthorized disclosure of Fleet deployment metadata from the default Kibana space.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

EPSS: 0.003 (19.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 20th percentile — 19.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-78603: held from 0.002 to 0.003.

EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-78603?
CVE-2026-78603 is a medium-severity vulnerability in Elastic Kibana, classified under Missing Authorization. CVSS score: 4.3/10. Published 2026-09-01.
How severe is CVE-2026-78603?
Medium severity. CVSS v3 base score is 4.3 out of 10.